Day 10: Wings, Air box, Boot cover & Harnesses

Realisation dawned towards the end of day 10 that I was in the 80/20 rule mode. 80% of effort will likely be the final 20% of the build. This thought occurred just after the second time I bashed my thumb with a hammer trying to peen the back of a boot cover fastener with the really annoying hammer and anvil took provided. But the day started with the rear wings, so back to there.

Rear Wings

This was an in the house on carpet kind of job. Its much easier than it looks, was something I was worried about beforehand but went very smoothly. Mainly because I am now really into riveting!

I used masking tape to tape the thin rubber edging strip around 3 sides of each carbon fibre stone guard, snipping triangles out of the corner areas to make the strip follow around the curves. I then stuck the whole thing to the wing using more tape and drilled out through the fine glass wing via the predrilled holes in the guards. 5 minutes of riveting later and I then peeled off the tape showing on the front face. The rest of the tape I left behind, hidden between the guard and the wing. Then repeated the other side.

Once the guards were fitted I attached them to the car. Or I tried, before I remembered that I had to cut out a chunk of wheel arch to ensure that it doesn’t snag on the radius arms. It’s surprising how much you need to cut out to make it fit. I used a hacksaw and a file to smooth the rough edges away.


I had no problem fitting the RHS arch, but one of the pre-installed rivnuts on the LHS side skin was not inserted correctly, sort of squashed inside and when screwing a bolt in it started rotating. So I had to drill out, which unfortunately kicked off a chain of events which made the rivnut rotate and grind down a bit of the skin. Once removed, I inserted a slightly larger rivnut and sorted the problem. Thanks to Craig here for helping me calm down during this painful exercise!

Air Box

This was one of the smallest jobs to do, but turned into one of the most painful. As previously mentioned, Caterham had supplied my chassis with the 3 rivnut holes drilled in the wrong places.

In the end, Derek provided me with a template to ensure I could mark the correct locations for the holes, a bunch of rivnuts and 3 new air box bobbins. Apparently I had been supplied with the wrong type of these too. The ones in my kit were long, the ones I needed were short. I found this out randomly during a conversation with him!

short bobbin (top) for SV 420R, long one for S3
I’m still not happy with the fact that I have extra holes drilled, and I will take this up at the post build check. Meanwhile, a job I should have completed with my eyes closed a week or so back was eventually completed after I borrowed Craig’s rivnut gun.

Boot Cover & Harnesses

My next objective was to get the seat in. But in sequencing akin to the “thigh bone connected to the knee bone” I needed to insert the roof strakes (for holding up the hood) before I could attach the boot cover, before I could attach the harnesses, before I could attach the seats!

The roof strakes were simple, but the picture in the assembly guide is for an S3, and the SV ones are laid out differently and shaped differently. But its fairly obvious what to do!

They need a self-tapping screw driving into a hole drilled into the boot top chassis member, and this needs to be done so that the first strake is 420 mm from the top of the boot top chassis.

Before you place the boot cover in position the metal strip inside the seam at the leading edge (seat back edge) has to be removed. Simply unpick the thread at one end, slide the bar out and then super glue the opened end back together. 

Then the cover is placed in position and I used a 5mm (only one I had, could have done with being 10mm diameter) leather cutting punch to cut out the 4 holes directly above the pre-drilled holes in the chassis for the harness fixings. I then used the same tool to poke through the flap of the rear carpet that was covering the same holes. 

I actually needed to make these holes bigger and used a Stanley knife blade to do so. I took my time to make neat larger holes, big enough for the harness bolts to just go through. In retrospect I could have been a little more aggressive here, as the holes are covered with the seat belt mounts, so no need to be super neat. 
And then I placed the boot cover in place and bolted the harnesses in. The harness bolts, mount spacers and washers were in the harness packs by the way. Knowing that will save you the 10 minutes of idiotic grovelling though every bag looking for them!

The order of the fixings is in the manual and you don’t seem to need to use the cardboard washers at all. The crush washer goes between the spacer and the belt itself. The regular washer goes directly between the bolt head and the belt.  I had also heard that other folks boot covers twisted a little when tightening the bolts to their final torque. So I squirted rubber lubricant around under each bolt to mitigate against this. It worked a treat. 

The important thing to note is that you have to think about the boot cover fitting around the roll bar and having enough material left to pull tight around the edge where the poppers go. With this in mind make sure that you don’t line the leading edge of the boot cover with the edge of the bulk head. It won’t give you quite enough wiggle room. Move it back around 5-10mm so it appears ‘stepped’ under the harness bolts. 

Once all of the harnesses were in place, Craig and I got to work on the poppers. Starting from rear central one, then working out and around keeping it all really taught. Easier with 2 people, but viable with one. 

Two super important tricks here. One, use masking tape under the boot lid and press it down when really tight over the existing make popper base on the chassis. It creates a perfect circlular indentation. I then used my paint pen to blob the centre point of this. 

Second important trick is to use a fabric punch. I didn’t have the right equipment here, but Andrew, my next door neighbour did. I selected the right sized hole and then one squeeze later a perfect little hole appeared. Simple. 

Then the pain of using the Duradot tool. It’s awkward because you need a sturdy base to wallop it on. Craig held a piece of wood in place against the bulk head and then I used a hammer to complete the job. Others have better hammering skills than I. My left thumb is still throbbing two days later!

But it was worth it, because the finished boot cover fits really well and is tight over the poppers. A very satisfying job to complete, and the first time I’ve ever fitted poppers. Not rocket science but still, every day is a school day!




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